Weather tracker: Record snowfall in eastern Russia leaves people stranded

A record-breaking snowfall event unfolded in far eastern Russia last week when the town of Petropavlovsk-Kamchatsky, located on the Kamchatka Peninsula’s east coast, received more than 1.8 metres (6 feet) of lying snow in places.Strong winds accompanying the snowfall caused extreme drifting of more than 3 metres against buildings and cars. Two key ingredients combined to cause such an extreme snowfall event. Strong Pacific low pressures dragged moist air from the tropics northwards, which clashed with cold Arctic air already over the region.Conveyor belts of tropical air are called atmospheric rivers and often bring heavy rainfall to places such as California. Atmospheric river snowfall events tend to be rarer and, for the Kamchatka Peninsula, particularly impactful.Heavy snow started falling in the early hours of Monday 12 January, and with snowfall rates of 2-5cm an hour at times, it continued until Tuesday evening, bringing 60-90cm of snow. As one system passed through, another approached, and the snow began again on Wednesday afternoon, not easing until Friday morning and bringing an additional 60-90cm widely across the region.Cars quickly became buried in snowdrifts, with residents digging tunnels through the snow to find their vehicles. People were seen sledding from roofs as snow piled up against buildings. Two people were killed when a buildup of snow fell from a rooftop. The process of clearing roads and building entrances has continued well into this week.In the Mediterranean, a slow-moving area of heavy rain associated with Storm Harry caused a historic rainfall event in north-east Tunisia on Tuesday, with several areas recording the highest rainfall totals since 1950. 242mm fell in the coastal city of Sayada – roughly five times the average for January, and about 70% of the yearly average – while 206mm was recorded near the capital, Tunis.The downpours caused flash flooding, carrying debris as large as cars through streets. Four deaths were reported in the town of Moknine, close to Sayada, including a woman who drowned inside her home. With roads and other transport links submerged, some communities were cut off entirely, hampering the already stretched response by emergency services, and schools and courts were among buildings closed in the wake of the disruption.Severe rainfall also affected neighbouring regions of Algeria, where two further flooding-related deaths were reported, and Libya, which also experienced damaging winds.Storm Harry also wreaked havoc across eastern parts of Sardinia, Sicily and south-west Italy, with heavy rain and strong winds between 18 and 21 January. Ogliastra in Sardinia had rainfall amounts five times higher than the January average in just three days with 548mm in Genna Tuvara and 489mm in Villagrande Bau Mandara. Similar rainfall amounts were seen in Sicily and Calabria in Italy, with 570mm in 72 hours in San Sostene. The extreme weather caused extensive damage to roads, buildings and infrastructure, with flooding, landslides and dozens of families evacuated from their homes.